books.google.co.uk - One of the greatest mysteries in reconstructing the history of life on Earth has been the apparent absence of fossils dating back more than 550 million years. We have long known that fossils of sophisticated marine life-forms existed at the dawn of the Cambrian Period, but until recently scientists had...https://books.google.co.uk/books/about/Cradle_of_Life.html?id=YJHBAolcIk8C&utm_source=gb-gplus-shareCradle of Life